I drive 50K miles per year in DC traffic and I'm right at 104K miles! I see no sacrifice in reliability. In fact, when Al of DynoFlash tuned my car on OCT 3rd, he couldn't believe I had that many miles and was pulling so hard and riding so smooth on stock shocks. In my research I could't find one first hand acount of the pulley causing an engine failure. I just take car of my EVO through proper service!
As always, when moding you car, only mod what you can afford to replace! If my engine lets go, I'll rebuild it stronger!

 

-

Can one of you guys (Rob or RedCloud) explain what the balance shaft does so that everybody understands and then install the pulley with piece of mind? I have a fairly good idea of how my engine works, but I don't know enough about this specific function to explain it myself... and this is critical in understanding the impact of the pulley.

-

 

This is a good start: http://en.wikipedia.org/wiki/Balance_shaft

 

-

I thought balance shafts countered the tortional vibration too... but in light of this article, it seems they're two seperate strains on the crankshaft. I'm beginning to wonder if shiroboi doesn't have a point then...

Can anyone offer any kind of alternate explanation/opinion on this?

-

 

Is there a Professional engine builder in the house? If so please speak up!

 

-

We would actually need a good engineer to have a look at this and tell us what he thinks. An engine builder deal with race engines which will have a lifespan of around 1000Km (600 miles) top... thus a small ammount of vibration and very subtle wear factors would probably not come into play for these guys.

BTW: Since I haven't taken my stock pulley off yet, I don't know if there's any rubber components to it. The last time I saw a pic of it, I was left with the impression that ours was a solid chunk of metal though...

-

 

I have had my stock pulley in hand several times and unless I missed something it is all metal and heavy as hell compared to the one I installed. All I can say is that I've had no issues and you can really feel the difference in mid-range power.

 

It's a big no-no on hondas. I really don't think it is worth it any risk.

 

-

If ours is a one piece part, that means it's not a tortional dampner and thus would just add stress to the crankshaft instead of partially removing it. So the lightened pulley would in fact be beneficial in that regard.

And I don't know about Honda's dampening techniques... and quite frankly I don't care that much. All I care about is our engine. Form one of the previous post by shiroboi, we know that the 3000GT had a two parts pulley that acted has a tortional dampner. If ours is solid, that means Mitsubishi has abandonned this dampning technique in his later engine designs... and the UDP is safe to use on our cars.

-

 

So from this thread theres 2 completely opposite opionions.

1) It's safe and won't damage the engine much, which a good friend also said, who happens to have helped build a mazda race car, although I didn't ask him about the vibrations on the crankshaft.

2) It's not worth the risk.

 

-

Well, now that we know you have a friend who could help us with this...

-

 

I can ask him about it, but it sounds like an issue that is going to vary from engine to engine.

He did say if there was every going to be a reliability issue it would be way down the road, possible acouple thousand mile before the engine would give out anyway.

 

I know I'm installing mine. I drive a lot (the car is 5 months old and it has 12k miles) so if it does damage the engine I'll be the first to warn you guys. If you don't trust it there are other ways to make hp.

 

I know... it would involve him taking a look at some technical stuff about our engine and then telling what he thinks. I,d understand if he's not willing to spend the time on this... but it would be great if he could.

In the meantime, I'll try to make 100% certain that our stock pulleys are a one piece part... that seems to make all the difference.

-

 

Redcloud, Can't be sure of engine wear until you take your engine apart and look at the crankshaft/bearings. And according to Mach V Racing, they saw a crankshaft shatter as a result of an overdrive pulley.

If its found that there isn't a harmonic dampener on our cars, then sign me up, I'll order a pulley. From some pictures, I couldn't really tell. But lots of guys took their stockers off, can anyone confirm that its one piece?

And this is exactly the kind of discussion that i wanted to get out of this thread. Just wanted the topic researched and looked into by all so we could come up with a reasonable conclusion.